Fuse



B. C. CANDEE AND W. N. PIERCE.

UNITED STA-TES PATENT OFFICE.

BERTRAM COLMAN CANDEE AND WILLIAM NICKLIS PIERCE, F BUFFALO, NEW

YORK, A SSIGNORS-TO PIERCE FUSE CORPORATION, OF BUFFALO,

A CORPORATION OF NEW YORK.

NEW YORK,

FUSE.

Patented Dec. 20, 1921.

Application led October 16, 1917, Serial No. 198,941. Renewed May 20, 1920. Serial No. 382,928.

T 0 a-ZZ- whom it may concern.'

rBe it known that we, BERTRAM C. CANDEE and WYILLIAM N. PIERCE, citizens of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented new and useful Improvement-s in Fuses, of which the following is a specilication. i l

This invent-ion relates to a fuse of that type in which the fuse-link is renewable when the same burns or blows ont, thereby enabling the casing, terminals and other permanent parts of the fuse which receive the fuse-link and coperate with the fuse-block7 to be used over and over again.

It is the objectof this invention to devise a fuse of this character which is very simple in construction, capable of being produced at low cost and also permits of conveniently and quickly renewing the fuse as well as preventing the use of the fuse in a fuseblock unless the parts are shifted relatively to each other into such a position that the fuse-link is completely inclosed and thereby insuring the safety of the persons handling the fuse and also guarding against the danger of fire adjacent to the fuse when the same blows out.

In the accompanying drawings:

Figure l is a vertical longitudinal section of a fuse embodying` the invention. Fig. 2 is a similar section taken on line 2 2, Fig. 1. Fig. 3 is an end view of the fuse. Figs. 4 and 5 are transverse sections taken on the correspondingly numbered lines in Fig. 1. Fig. 6 is a detached side elevation of the inner tubular section of the fuse.. Fig. T is a fragmentary side View of one end of the outer tubular section of the fuse casing. Fig. 8 is a fragmentary side view of the outer casing section showing a modified form of the means for arresting the movement of the same in the direction in which the fuse casing is closed.

Similar characters of reference indicate corresponding parts throughout the several views.

The inclosing casing ofthe fuse comprises inner and outer tubular sections 1, 2, which fit one into the other and are adapted to slide lengthwise relatively to one another in the manner of a telescope for the pur pose of opening or closing the fuse for introducing the fuse-link into the space within the casing. These casing sections are constructed of an electric insulating material such as vulcanite and are preferably of the same length or substantially so when the sections are telcscoped one within the other. rlhe outer casing section is provided at one end and on diametricallv opposite sides thereof with longitudinal`notches 3. 3, eX- tending inwardly from the edge thereof, but the opposite end of this casing section is unnotched. The inner casing section is provided on one side with a longitudinal filling opening 4. This opening should preferably be equal in length to the fuse link 5 to permit of introducing the latter sidewise through this opening and into the inner cas- 111g section. This opening may be uncovered for this purpose by sliding the outer casing section lengthwise away from this opening. l y

G, 7, represent two outer end caps which are preferably cup-shaped and constructed of sheet metal and which in the normal or closed position of the casing are arranged atopposite ends of the two casing sections with their concave sides facing inwardly. One of these caps, for instance G, is secured to the outer casing section by suitably indenting the cylindrical portion or flange thereof. as shown at 8, so that these indentations engage with the outer casing section and act as spurs or anchors which prevent this cap from )ailing off the respective casing section. T e other outer end cap 7 ts over the opposite end of the outer casing section with a sliding fit, so that these parts can be separated lengthwise from each other and also pushed together for opening or closing the casing.. Each of these outer end caps is provided with a central terminal opening 9 which preferably is constructed in the form of a slot extending transversely across the transverse plate of this cap. and each of these outer end caps is also provided with vent openings 10` two of which are preferably formed on the plate of the cap on opposite sides of the central terminal` vcentral part of its plate with a terminal opening 13 and on opposite sides of this terminal opening with vent openings 111, as best shown in Figs. 2, 4C and 5. Tithin each of the spaces between a pair of end caps and preferably extending across the vent openings of the inner cap, is arranged a screen of woven wire 15 which operates to vprevent any flashes of lire from passing from the central part of the casing which contains the fuse-luik through the vent openings l-l, 10 of the inner and outer caps, but will permit the escape ot' any gases from the casing when the fuse blows out. Internal pressure within the casing is by this means avoided as would be liable to occur if no vent were provided, while at the same time guarding against setting tire to anything in the immediate vicinity of the fuse.

Within each of the spaces 12 between a pair of end caps is arranged a metal bridge which may be variously constructed, but in the preferred form comprises a cross piece 16, two attaching lugs 17, 17, arranged or opposite sides of the cross piece and a longitudinal terminal lug 40 projecting from the central part of the cross piece through the central opening 13 of the respective inner end cap and into the adjacent part of the compartment within the inclosing casingu One of these bridges, for instance, the one arranged at the left hand end of Figs. 1 and 2, is connected only with the adjacent end ot the inner casing section and the respective inner end cap by means of coupling screws 18 passing through corresponding openings formed in the inner casing and the flange on this end cap while theirthreaded inner 'ends engage with threaded openings in the Side lugs 17 of the respective bridge while their heads are countersunk in the outer side of the inner casing section. l The other bridge is connected with both inner and outer caps at the respective end of the inner casing section, this being preferably accomplished by means ot coupling screws 19 passing transversely through corresponding openings in the flanges of the respect-ive end caps and engaging their threaded inner ends with internally threaded openings in the side lugs of the respective bridge while their heads bear against the outer side of the flange ot' the respective outer cap. In the assembled position of the parts and when the fuse casing is completely closed, the notched end of the outer casing section bears against the inner side of the transverse plate of the end cap 7, this being possible by inner section.

20, 21 represent two metal terminals whereby the fuse is connected with the terminals of a fuse-block. Each of these fuse terminals is provided with a comparatively' wide and ilat outer part which engages'with the terminal of the fuse block and is arranged in the terminal slot of one of the outer caps and a narrow inner part which eX- tends across the space between the companion inner and outer caps and through the central terminal opening of the respective inner cap and into the adjacent part of the space within the casing. ln the space be` tween each pair of capsthe companion terminal and bridge are connected, preferably, by means of a rivet 22, as shown in Figs. l, Qand 4;. The inner parts of each terminal and the adjacent terminal lug of each bridge are detachably connected with one end ot the fuse-link, this being preferably accomplished by means of a clamping screw 23 having its threaded shank engaging with an internally-threaded opening formed' in the inner end of the respect-ive terminal and the adjacent part of the terminal lug ot the respective bridge and provided at one end with a head between which and the terminal one end of the fuse-link is adapted to be clamped. Complete withdrawal of the clamping screw 28 is prevented by providing its threaded end with a stop 25 which is preferably formed by means ot a bur or fiange at this end ot this screw. For convenience .in attaching the fuse-link to the inner ends of the terminals, one end ot the saine is provided with a longitudinal slot or notch 26 which extends to the end of the link and at its opposite end with a lateral slot 27 which extends transversely to one side thereof. By this means the longitudinallyslotted end of the link may be rst engaged with its respective clamping screw and then the fuse-link may be swung on this screw as a fulcrum for engaging its transversely slotted end with the other clamping screw, after which bot-h of these screws may be tightened for securely holding the fuse-link in place. y

Lengthwise movement of the two casing sections relatively to each other for separating them and opening the casing is limited so as to prevent complete separation of these parts, which means are preferably so organized that they also aid in prevent-ing these two casing sections from rotating one relative to the other and thereby always retain these casing sections in their proper position relatively to each other. This stopping andguiding device preferably comprises a longitudinal slot 28 formed in the inner casing section opposite to its filling opening f1 and providing the inner side of the outer casing section with a stopping and guiding pin or lug 29 which engages with this slot. pon pulling the two casing sections apart, the stop pin 29 of the outer casing section engages with the rear end of the slot 28 in the inner casing section and limits the movement of these parts relatively to each other at a point at which the outer ends of the terminals 20, 21are still arranged within the terminal slots of the outer caps, thereby preveiit-ing disarrangement of these parts and permitting the same to be again quickly pushed inwardly one over the other for closing the inclosing casing of the fuse after a new fuse link has been introduced into the casing and secured to the terminals.

Inasmuch as it is impossible to attach the outer ends of the terminals of this fuse to the terminals of a fuse-block without conipletely closing the casing sections, the danger of fire or injury to the operator is positively prevented inasmuch as the fuse is incapable of use until the parts have been restored to their proper and safe position.

Instead of providing the outer casing section with notches for the reception of the coupling screws 19, this section may be divided so as to form a body portion 3() and an end ring 31 confined within the end cap by the screws 19 which engage with cooperating notches 32, 33 in the opposing ed es of the body 30 and ring 31, as shown inig. 8.

Owing to the simplicity of the several parts which comprise this fuse, the ease with which the same can be manufactured and the low cost at which the same can be assembled, this fuse as a whole is less expensive than those heretofore in use. Furthermore. this fuse can be very quickly opened and closed and refilled with a new fuse-link in the event that this becomes necessary without requiring any special tools for this purpose and without the need ot any skilled help.

XVe claim as our invention:

1. A fuse provided with a casing having inner and outer tubular sections of insulating material which are slidable lengthwise relatively to one another, said inner section having an opening in its side for the introduction of a fuse link into the casing, in combination with outer end caps of metal one secured to one end of the outer casing section and the other secured to the opposite end of the inner casing section` and each of said outer end caps being provided with an opening, inner end caps of metal secured to the opposite ends of the inner casing section and each provided with an opening and separated from the adjacent outer end cap by an intervening space, a terminal arranged in said openings of the corresponding end caps and having an inner end portion arranged within the casing and an outer end portion arranged outside of the casing, a bridge arranged in the space between each pair of inner and outer caps and secured to the respective inner cap and terminal and provided with a part projecting through the respective inner cap, and means for attaching a. fuse link to the inner ends of said terminals.

2. A fuse provided with a casing having inner and outer tubular sections of insulating material which are slidable lengthwise relatively to one another, said inner section having an opening in its side for the introduction of a fuse link into the casing, in combination with outer end caps of metal, one secured to one end of the outer casing section and the other secured to the opposite end of the inner casing section, and each of said outer end caps being provided with an opening, inner end caps of metal secured to the opposite ends of the inner casing section andeach provided with an opening and separated from the adjacent outer end cap by an intervening space, a terminal arranged in said openings of the corresponding end caps and having an inner end portion arranged within the casing and an outer end portion arranged outside of the casing, a bridge arranged in the space between each pairof inner and outer caps and secured to vthe respective inner cap and terminal and provided with a part projecting through the respective inner cap, and means for attaching a fuse link to the inner ends of said terminals and the inner parts of said bridges.

3. A fuse comprising a casing having inner and outer tubular sections of insulating material which are slidable lengthwise relatively to one another, said inner section having an opening in its side for the introduction of a fuse link into the casing, outer end caps of metal, one secured to one end of the outer casing section and the other secured to the opposite end of the inner casing section, and each of said outer end caps being provided with a. terminal opening and a. vent opening, inner end caps of metal secured to opposite ends of the inner casing section and each provided with a terminal opening and a vent opening, and a terminal arranged in the terminal openings of each pair of adjacent end caps.

4. A fuse comprising a casing having inner and outer tubular sections of insulating material which are slidable lengthwise relatively to one another, said inner section having an opening in its side for the introduction otl a fuse link into the casing, outer end caps ot metal, one secured to one end of the outer casing section and the other secured to the opposite end e5 the inner casing section and each of said outer end caps being provided with a tcrniial opening and a vent opening, inner end caps of metal secured to opposite ends of the inner casing section and each provided with a terminal opening and a vent opening, a terminal arranged in the terminal openings of each pair of adjacent end caps, and a screen arranged between the end caps of each pair.

5. A fuse comprising inner and outer tubillar casing sections ot' insulating material which are slidable lengthwise relatively to each other, said outer casing section being provided at one end with a notch while its opposite end is unnotched` outer end caps of metal one of which is secured to the nnnotched end of thc outer casing section while the other is slidable lengthwise on the opposite notched end ot the same, inner end caps of metal arranged at the opposite ends ot said inner casing section,- a screw arranged in the notch of said outer casing section and connecting the outer and inner caps on the respective ends 0f the casing sections, and terminals arranged on said caps and ada )ted to be connected within the casing by a use link.

t3. A fuse comprising inner and outer tubular casing sections of insulating material which are slidable lengthwise on each other and the inner section being provided With an opening for the introduction of a fuse into the casing and a longitudinal stop and guide slot, a stop and guide projection arranged on the outer casing section and projecting into said slot, and terminals mounted on opposite ends ot' said inner casing section and adapted to be connected within the casing by a 'fuse link.

BER'IRM COLMN CANDEE. WILLIAM NCKLS PIERCE. 

